Getting to Know LiDAR

I’ve worked with a lot of different types of geospatial data in my years at ITT VIS, but one type that I’ve had relatively little experience with is LiDAR. So, when ITT VIS announced that we would be releasing a new LiDAR application, E3De, I figured it was time to come up to speed. Here are a few things I’ve learned and helpful resources I’ve found, along the way:

What is LiDAR?

LiDAR = Light Detection and Ranging. In a nutshell, a LiDAR sensor measures distances by sending out and recording the return of laser pulses. A LiDAR system collects 3D data in the form of a point cloud. Here are some of the advantages of LiDAR:

Can be collected day or night.

Has relatively high accuracy (around 10 to 50 cm vertically and horizontally for airborne LiDAR).

Can penetrate through some features, such as trees.

Is less expensive and faster than classic photogrammetry.

What do you use LiDAR for?

LiDAR is used for many applications in many fields:

Field

Example Application

Agriculture

Estimate sun exposure of fieldsDetermine where to apply fertilizer

Archaeology

Plan field campaignsFind features in microtopography revealed below vegetation
Find broad features invisible from ground

Determine height of features warfighters will encounterFind features such as tanks
Detect aerosol clouds of biological or chemical agents at a distance

Hydrology

Surface hydrology modeling

Urban

Line of sight analyses3D models of urban areas
Finding buildings

Hazards Detection, Mitigation

Hazard mapping (fire, flood, landslide)

Film

Create CG environments

LiDAR for geospatial work is usually mounted on an airborne platform and pointed toward the ground. But it can also be non-airborne and pointed in any direction. For example, it can be used for meteorological and astronomical applications, and to help robots avoid obstacles. Some police speed guns use LiDAR. The band Radiohead even made their “House of Cards” video using LiDAR to model environments and people.

How do you get LiDAR data?

Many LiDAR users hire a commercial company to fly a LiDAR system over their area of interest. You can also download previously collected LiDAR datasets:

There will be an International LiDAR Mapping Forum in Denver, January 23-25, 2012, including intro to LiDAR workshops (look for me there). Check the LiDAR Resources section of this site for LiDAR system operators around the world.